Electrochemiluminescence resonance energy transfer of MnCO3 for ultrasensitive amyloid-β protein detection

Abstract

A composite material MnCO3/poly(diallyl dimethyl ammonium chloride) (PDDA)/Ag with excellent electrochemiluminescence (ECL) performance and high biocompatibility was prepared by adding MnCO3 and PDDA to silver nanoparticles (AgNPs). MnCO3/PDDA/Ag and Au@SiO2NPs were used as ECL donors and acceptors, respectively. Thus, an effective ECL–resonance energy transfer (RET) sensing platform was established. In a potassium persulfate (K2S2O8) medium, MnCO3 exhibited ECL emission with an ECL band appearing at 500–600 nm. In addition, Au@SiO2 nanoparticles showed a UV–visible absorption at 450–650 nm. The ECL emission spectra of MnCO3 overlapped with the absorption spectra of Au@SiO2NPs. The effective ECL quenching resulted in a good response to the concentration of Aβ42 in serum samples. The linear range was 5 fg ⋅ mL−1 to 100 ng ⋅ mL−1, and the detection limit was 2 fg ⋅ mL−1. The recovery ranged from 97.7% to 104%. The high-efficiency ECL–RET immunosensor has potential application in detecting human serum Aβ42 and other biomarkers, and can be used for the early screening of diseases.